Lee Seung-Jae, Jeon Seong-Ran, Song Young Ho, Choi Young-Jun, Oh Hae-Gon, Lee Hae-Yong
Korea Photonics Technology Institute, Gwangju 61007, Republic of Korea.
LumiGNtech Co., Ltd., Gwangmyeong, Gyeonggi 14322, Republic of Korea.
J Nanosci Nanotechnol. 2021 Sep 1;21(9):4881-4885. doi: 10.1166/jnn.2021.19258.
We report the characteristics of AlN epilayers grown directly on cylindrical-patterned sapphire substrates (CPSS) by hydride vapor-phase epitaxy (HVPE). To evaluate the effect of CPSS, we analyzed the threading dislocation densities (TDDs) of AlN films grown simultaneously on CPSS and flat sapphire substrate (FSS) by transmission electron microscopy (TEM). The corresponding TDD is measured to be 5.69 x 10 cm for the AlN sample grown on the CPSS that is almost an order of magnitude lower than the value of 3.43 × 10 cm on the FSS. The CPSS contributes to reduce the TDs originated from the AlN/sapphire interface via bending the TDs by lateral growth during the coalescence process. In addition, the reduction of direct interface area between AlN and sapphire by CPSS reduce the generation of TDs.
我们报告了通过氢化物气相外延（HVPE）在圆柱形图案蓝宝石衬底（CPSS）上直接生长的AlN外延层的特性。为了评估CPSS的效果，我们通过透射电子显微镜（TEM）分析了在CPSS和平坦蓝宝石衬底（FSS）上同时生长的AlN薄膜的位错密度（TDD）。对于在CPSS上生长的AlN样品，测得相应的TDD为5.69×10⁹ cm⁻²，这几乎比在FSS上的3.43×10¹⁰ cm⁻²的值低一个数量级。CPSS通过在合并过程中通过横向生长弯曲TDs，有助于减少源自AlN/蓝宝石界面的TDs。此外，CPSS减少了AlN与蓝宝石之间的直接界面面积，从而减少了TDs的产生。
